Machines that use engines, including diesel engines, gasoline engines, gaseous fuel-driven engines, and other engines known in the art, often produce a mixture of polluting emissions. These emissions may include gaseous and solid material, such as, particulate matter, nitrogen oxides, and sulfur compounds. Heightened environmental concerns have led regulatory agencies to increase the stringency of emission standards for such engines, forcing engine manufactures to develop systems to further reduce emission levels.
One type of device used by manufacturers to reduce machine emissions is a particulate filter configured to remove particulate matter from an exhaust stream. A particulate filter includes a filter assembly located in an exhaust system and configured to trap particulate matter. While such filters can reduce emission levels, over time the filters can become clogged and less effective at reducing emission levels. To remove trapped matter, particulate filters may be periodically regenerated, whereby the filter temperature is raised to burn off particulate matter and remove it from the filter. However, filter regeneration can reduce the operational lifetime of the filter and can require additional energy to raise the filter temperature. Therefore, limiting filter regeneration cycles is desirable.
Filter performance may also be affected by the flow of exhaust gas entering the filter. For example, a non-uniform flow of exhaust gas can overload some regions of a filter by concentrating gas flow, and hence particulate matter, through certain regions of the filter system. Such uneven gas flow may accelerate clogging of the filter regions exposed to higher gas flows, leading to more frequent filter regenerations. Therefore, filter performance may be improved by providing a generally uniform flow of exhaust stream into the filter to evenly distribute the flow of particles through the filter, reduce uneven filter clogging, and decrease the frequency of filter regeneration.
One device configured to more evenly distribute exhaust gases is described in U.S. Pat. No. 6,745,562 (hereinafter “the '562 patent”) of Berriman et al., issued on Jun. 8, 2004. The '562 patent describes a flow diverter configured for placement in an exhaust system. The diverter includes a structure with a central hole and conical walls configured to divert exhaust flow from a small diameter conduit to a larger diameter conduit immediately upstream of a catalytic converter.
While the device of the '562 patent may redistribute a flow of exhaust gas, the device can be further improved. In particular, the device of the '562 patent may not produce a sufficiently uniform flow of exhaust gas, and the device may create unnecessary backpressure within the exhaust system. Further, the device of the '562 patent may be costly to manufacture and may not be readily adaptable to operate with a range of differently sized exhaust systems.
The disclosed flow assembly is directed to overcoming one or more of the problems described above.